A historic mistake. Again

What is it about the word historic that makes the yahoo.com writers lose all sense? This would be correct only if they pronounce the word as istoric (and I’m not sayin’ they don’t):

The indefinite article an goes before a word that starts with a vowel sound, regardless the word’s first letter. So, in the U.S., it’s an herb (since we don’t pronounce the H), but in the U.K. it’s a herb (since they do).

It is, though, fairly standard British English usage. (As in ” ‘urricanes ‘ardly ‘appen”). Given that the writing staff seems to be hosted in Mumbai, which has a certain British Empire background, it’s (more or less) understandable,

(One of these days, I’ll look into why military officers’ hats are so weird.)